Predicting germination response of four cool-season range grasses to field-variable temperature regimes

摘要: Abstract Germination of non-dormant seeds under variable-temperature conditions can be predicted from constant-temperature germination data if it is assumed that instantaneous rate independent thermal history. Thermal-response models this type have not been validated simulated field-variable temperature vary in diurnal pattern, range and longer-term trends mean–daily temperature. The purpose experiment was to evaluate response thickspike wheatgrass (Elymus lanceolatus), bluebunch (Pseudoroegneria spicata), Sandberg bluegrass (Poa sandbergii) bottlebrush squirreltail elymoides) both constant regimes the laboratory. It hypothesized history assumption valid could used accurately estimate response. Seeds were germinated at seven temperatures between 5 35°C, 18 simulating six planting dates three field sites. Predictions time accurate within a fraction 1 day up cumulative percentage 70% for wheatgrass, 60% 55% squirreltail. concluded that, tested experiment, thermal-history earlier-germinating subpopulations.